Which of the following is the correct file extension for a C# source file?

• A. .csharp
• B. .cs
• C. .c
• D. .cpp

Which method serves as the entry point of a C# program?

• A. Start()
• B. Run()
• C. Main()
• D. Begin()

Which of the following is a value type in C#?

• A. String
• B. Array
• C. int
• D. Class

Which keyword is used to handle exceptions in C#?

• A. handle
• B. exception
• C. try
• D. catch

Which operator is used for string concatenation in C#?

• A. +
• B. &
• C. concat()
• D. join()

Which keyword is used to define an interface in C#?

• A. class
• B. struct
• C. interface
• D. abstract

Which collection in C# stores key-value pairs?

• A. List
• B. Dictionary
• C. Queue
• D. Stack

What is the main purpose of delegates in C#?

• A. Handle errors
• B. Reference methods
• C. Create classes
• D. Define variables

Which LINQ keyword is used to filter data?

• A. select
• B. where
• C. group
• D. orderby

Which class is used for reading text files in C#?

• A. FileWriter
• B. StreamReader
• C. FileReader
• D. TextReader

Which keyword is used in C# for asynchronous programming?

• A. sync
• B. wait
• C. async/await
• D. parallel

Which principle in SOLID stands for 'Open-Closed Principle'?

• A. Software entities should be open for extension but closed for modification
• B. A class should have one reason to change
• C. High-level modules should not depend on low-level modules
• D. Depend on abstractions, not on concretions

Which namespace is used for multithreading in C#?

• A. System.IO
• B. System.Threading
• C. System.Linq
• D. System.Net

Which ORM is commonly used with C# for database operations?

• A. Hibernate
• B. Sequelize
• C. Entity Framework
• D. Dapper

Which mechanism in C# allows examining metadata at runtime?

• A. Reflection
• B. Polymorphism
• C. Generics
• D. Serialization